British coronavirus variant can spread quickly in Netherlands, virologist says

The Netherlands must "seriously take into account" that the extra contagious B117 variant of the coronavirus from the United Kingdom will also spread quickly here, Marion Koopmans, professor of virology at Erasmus MC in Rotterdam, said to NRC.

On Wednesday, public health institute RIVM reported that at least 50 people in the Netherlands have tested positive for this variant of the coronavirus. In addition, a random sample of 10 thousand positive Covid-19 tests showed that the British variant is already present in many places in the Netherlands, with between 1 and 5 percent of positive tests involving this variant. "It popped up in various places in the country," Koopmans said. "So far usually at a very low level, but that can expand quickly."

Koopmans and GGD Rotterdam-Rijnmond investigated the largest outbreak with the B117 variant in the Netherlands so far, at the Willibrord School in Bergschenhoek late last month. Over 750 pupils, teachers and housemates around this primary school were tested for Covid-19 and at least 30 people turned out to have the B117 variant of the virus.

"All primary school teachers and pupils who tested positive were found to be infected with the British variant. About 10 percent of the people in the school children's families tested positive, some of whom also had the British variant. But it is now also clear that a third generation of infections has already occurred in which the contacts of those families have been infected with the British variant."

The emergence of this coronavirus variant in the Netherlands will "certainly play a role" in the government's decision on whether or not to extend the lockdown past January 19 and keep schools closed. "It is not yet clear whether children are particularly susceptible to this variant," Koopmans said to the newspaper. "But the cluster in Bergschenhoek does show that children can at least play a role in its spread."

Exactly how much more contagious the B117 variant of SARS-CoV-2 is, is not yet clear. Reports from the United Kingdom state up to 72 percent more contagious. "Of course, the calculation of infectivity also includes a behavioral factor," Koopmans said to NRC. "And when that variant expanded strongly in England in mid-November, the corona measures there were more flexible than now in the Netherlands." 

"But there are also other indications that can convince me that this variant is a lot more contagious. British research shows that the reproduction number of this variant is higher under the same conditions compared to the original virus. You also see more virus RNA in samples from people infected with this variant. That is not the same as more infectious virus particles, but it does point in the same direction," Koopmans said.